Maybe a friend recently sang the praises of her IUD, an excited gleam in her eyes as she tried to get you to join the club. Perhaps you’ve had a few too many broken condoms ruining the moment. Or maybe you want the option of an incredibly effective, reversible, yet hormone-free method of birth control.

There are plenty of reasons why you might consider an IUD, but before you settle on one, there are few things you need to know.

IUDs are split into two categories: hormonal and non-hormonal. Hormonal IUDs (like Mirena, Kyleena, Liletta, and Skyla) use varying levels of progestin, the synthetic form of the hormone progesterone, to prevent pregnancy. Progestin thins your uterine lining, thickens cervical mucus so it’s harder for sperm to swim through, and partially suppresses ovulation so sometimes there’s no egg to be fertilized in the first place, according to the Mayo Clinic. There’s only one non-hormonal IUD, ParaGard, which releases copper that bathes the lining of your uterus, creating an inflammatory reaction that’s toxic to sperm, according to the Mayo Clinic.

IUDs—like any form of birth control—can be perfect for some people and inadvisable for others. It all comes down to your unique medical history and anatomy as well as your lifestyle and preferences when it comes to contraception. So be prepared to have a thorough discussion with your doctor to figure out if an IUD is right for you. In the meantime, we’ve outlined a few things to consider before your appointment so you’re better informed about what an IUD could mean for you and your period.

Here are a few reasons why an IUD could be an excellent choice for you.

1. You want highly effective birth control.

What research has been done shows that hormonal IUDs fail just 0.2 percent of the time while the copper IUD fails 0.8 percent of the time. This means fewer than one out of 100 women will get pregnant each year when using an IUD. A lot of this comes down to the fact that IUDs are hard to mess up.

Birth control pills, on the other hand, have a failure rate that ranges from less than 1 percent with perfect use (using it consistently and correctly every single time) to 9 percent with typical use (when you also factor in people who occasionally use it imperfectly or incorrectly). So if you’re worried about messing up your birth control, an IUD might be a good choice for you.

To put it simply, IUDs are “one of the best methods of contraception that we have,” Lauren Streicher, M.D., an associate professor of clinical obstetrics and gynecology at Northwestern University Feinberg School of Medicine, tells SELF. The only reversible contraceptive that’s more effective than the IUD is the implant, which was found to have a 0.05 percent failure rate. That implant (Nexplanon) goes in your arm and can be used for up to three years.

2. You want protection for years but also want your fertility to return ASAP when you stop using contraception.

Mirena and Kyleena are recommended for up to five years, Liletta is recommended for up to four years, and Skyla is recommended for up to three years. ParaGard, on the other hand, can be used up to 10 years. So if you’re looking for long-term birth control (rather than, say, only-use-it-when-you-need-it birth control like condoms), this could be a great option.

Then, if you decide you want to try to have a baby, just schedule an IUD removal with your doctor (the process is typically pretty painless, experts say), and you can start trying to conceive right away. “We usually see a woman’s ability to conceive return within a cycle,” Jessica Shepherd, M.D., a minimally invasive gynecologist (meaning she uses robotics and/or laparoscopy to do surgery) at Baylor University Medical Center at Dallas, tells SELF. For comparison’s sake, it can take up to 10 months or more for ovulation to start back up after stopping the birth control shot.

3. You want a BC option that needs basically no maintenance.

With methods like the pill, the ring, and the shot, you have to think about your birth control on a regular basis. But IUDs are different.

After the insertion, there’s not much maintenance involved. Your doctor may just recommend you check the strings hanging from the bottom of the IUD once a month. You’ll also typically have a follow-up appointment about a month after the insertion just to make sure the IUD is still properly in place.

4. You want a lighter—or nonexistent—period.

Conditions like endometriosis and uterine fibroids can make your period a living hell, full of debilitating pain and excessive bleeding. In that case, a hormonal IUD may help with that.

Since the progestin in hormonal IUDs thins your uterine lining, there’s less matter to expel during your period, so you can experience lighter flows. This can also have the blessed effect of reducing period cramps, since prostaglandins, hormone-like chemicals that cause uterine cramping, actually come from cells in your uterine lining. When you’re not making as much of that lining to begin with, your prostaglandin production can decrease, relieving cramps.

If you experience heavy or crappy periods, Dr. Streicher recommends opting for a hormonal IUD with a higher dose of progestin. “You have the greatest likelihood of your period disappearing or being suppressed with [that],” she says. Or, if you like having a monthly reminder that you’re not pregnant, it might be better to go with a lower-hormone IUD that still protects you but may still allow you to get your period, Dr. Shepherd says.

5. Your doctor suggested birth control without estrogen.

Hormones aren’t for everyone. There are several reasons why your doctor might want to steer you away from birth control methods that contain estrogen, like the pill, the ring, and the patch, and towards a non-hormonal IUD or one that only uses progestin. Here are some of the most common reasons your doctor may advise against using BC with estrogen:

You currently have breast cancer. There are many types of breast cancer, including those that are estrogen-receptor positive. That means they need estrogen to grow, so taking an estrogen-containing form of birth control could stimulate them, Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology and reproductive sciences at Yale Medical School, tells SELF.

You’re breastfeeding. Estrogen interacts in various ways with prolactin, a hormone that’s necessary for breastmilk production. Adding too much to your body via birth control could suppress milk supply, Dr. Minkin says, so a doctor will likely steer you in the direction of something like an IUD or the progestin-only minipill.

You have a history of blood clots. Estrogen increases the production of clotting factors in your blood, especially if you’re a smoker. This can make it more likely that you’ll develop a blood clot, which is one of the main causes of stroke. (A family history of clots doesn’t raise your risk quite as much, but it’s still something you should mention to your doctor.)

You have high blood pressure. If you have hypertension, you’re already at increased risk for health crises like stroke and heart disease. Combination birth control can boost that risk even more because estrogen can raise blood pressure, Dr. Minkin says. This isn’t much cause for concern if you have low or normal blood pressure, and if you have well-controlled high blood pressure, your doctor may consider putting you on a low-dose pill and monitoring your health, she explains. But they may also advise against estrogen in your birth control altogether.

You’re a smoker. Smoking is obviously incredibly detrimental to your heart health. It creates a host of negative effects, like harming your blood cells, damaging the structure and function of your blood vessels, and making it harder for your heart to function overall, according to the National Heart, Lung, and Blood Institute.

Being a smoker and taking an estrogen-containing birth control method can increase your risk of blood clots, heart attack, and stroke. This is especially true if you’re over 35 and smoke 15 or more cigarettes a day, according to the Mayo Clinic.

6. Or, you'd prefer a birth control option without any hormones.

Some just aren’t into the idea of taking hormonal birth control. Maybe you’ve had a bad reaction to one in the past—Dr. Minkin notes that a lowered libido is a common complaint—and prefer to go sans hormones in the future. In that case, a copper IUD might be a good choice for you.

While there are other hormone-free methods of birth control like condoms and fertility-based awareness methods, your overall options are pretty limited. If hormones aren’t your bag, talk to your doctor about the possibility of going with the copper IUD.

7. You have a pretty high pain tolerance.

Listen, the insertion procedure can hurt. For some people, it will just be mildly uncomfortable, but for others it can hurt a lot. The pain varies from person to person, but it’s something to keep in mind. Another thing to keep in mind: that you only have to do it once and then you’ll have birth control that lasts for years.

Even with all their benefits, IUDs aren’t for everyone. Here are a few reasons why a different birth control may be better for you.

1. You hate the idea of having a device inside you.

Maybe you like the sense of control that comes with taking a pill every day or you’d prefer a method that you can start or stop at any time (without needing to go to your gynecologist for an insertion or removal). IUDs have been established as safe and effective for most birth control users, but you also need to feel completely comfortable with your birth control method.

It’s true that IUDs come with a small risk of expulsion, which is basically when your body starts to push out your IUD. According to the limited research on IUD expulsion, the average incidence rate is between 3 and 5 percent of all IUD users and 5 to 22 percent of adolescent IUD users, says the American Congress of Obstetricians and Gynecologists. But it’s important to note that this research was done in 2009 and 2010 and only looked at Mirena and ParaGard, not any of the newer (often smaller) options that have been developed over the last several years. (Some women whose IUDs have expelled still choose to get another one because of the benefits they offer.)

IUDs also come with the risk of perforation, which happens when an IUD pushes through your uterus, although this is even less likely than the chance of expulsion. One study published in the journal Conception in 2015 found that out of 61,448 women who had an IUD, only 81 (0.13 percent) reported having a perforation.

2. You want to control when you get your period.

While a hormonal IUD can make your period lighter or even stop it completely, it won’t let you pick and choose when you menstruate. That’s something you may be able to do with birth control pills, depending on the type and the brand, according to the Mayo Clinic. There are even some pills specially designed to lengthen how long you go between periods. If you prefer to work your period around your racing schedule or vacations, the IUD might not be right for you.

3. You want to get pregnant in the next year or so.

Technically, you could use an IUD until you’re ready to start trying and be just fine, but that’s not exactly cost-effective, Dr. Streicher says. IUDs can be expensive if your insurance doesn’t cover them.

Under the Affordable Care Act’s contraception mandate, employer-provided health insurance had to cover at least one form of each of the FDA-approved methods of birth control without a copay. Closely held private companies (meaning they have a limited number of shareholders) could decline to cover birth control if they objected for moral or religious reasons. In October 2017, the Trump administration rolled back that mandate, allowing any employer or insurer to refuse to cover birth control on those grounds.

So, if the type of IUD you want isn’t covered by your insurance, you could end up paying a lot, which may only make sense if you plan to use the IUD for years. An October 2017 report from Amino, a health care research company, found that IUDs could cost around $1,000 out of pocket. Over time that might still be cheaper than the pill or another method, but it’s worth taking into consideration.

Plus, while manageable, IUD insertion and removal are still medical procedures, and the insertion in particular can be painful. Taking another kind of birth control until you’re ready to get pregnant could be less taxing than going through all of that in a short timeframe.

4. You’re dealing with a pelvic health issue.

While most women are fine to have an IUD inserted, there are a few exceptions. One is if you have a condition like a sexually transmitted infection or pelvic inflammatory disease (this stems from untreated STIs), Dr. Shepherd says. In those cases, doctors want to make sure everything is cleared up before they add an IUD to the mix, she says. (If you’ve had an STI in the past and it’s gone, though, you should be fine.)

Similarly, if you have any heavy bleeding, unusual vaginal discharge, or any other vaginal health issue, your doctor will want to try to figure out what’s going on before putting something up there.

“Estrogen has some wonderful properties,” Dr. Minkin says. For one, it helps to prevent breakthrough bleeding, which can be a problem with progestin-only birth control. While estrogen promotes the growth of your endometrial lining, it also helps stabilize it so it’s less likely to break up into little bits and cause spotting when it shouldn’t, Dr. Minkin says.

Estrogen can also help diminish or even entirely banish acne for some people. “Estrogen acts as an antidote to testosterone, which is a main contributor to acne,” Dr. Minkin says. This is why estrogen-containing birth control can be a great option for someone with polycystic ovary syndrome (PCOS), she explains: Since elevated levels of male hormones like testosterone can contribute to the hallmark symptoms of PCOS, like tough-to-treat acne and excessive facial and body hair, using birth control with estrogen may provide relief.

Taking a birth control with estrogen can also help combat vaginal dryness, if that’s been an issue for you. “The vaginal mucosa is very sensitive to a lack of estrogen,” Dr. Minkin says.

Ultimately, choosing a birth control method is like any other major medical decision and there are a lot of factors to consider. Come to your appointment knowing what you do and don’t want in a birth control, and your doctor can guide you from there.

Correction: This article was corrected to reflect that the Skyla IUD can be used to prevent pregnancy up to three years and that the Liletta IUD can be used to prevent pregnancy up to four years.